Kansas, like the rest of the country, has seen less than half the number of people getting sick from West Nile virus so far this year as normal.
The Kansas Department of Health and Environment says it's seen 13 cases reported in the state, compared with 32 at this point in 2007. Nationally, health officials say they've recorded 712 West Nile cases, compared with 1,982 last year.
But they can't figure out why.
West Nile is carried by mosquitoes. Health officials say there may have been environmental conditions this year that prevented the disease from spreading as rapidly.
But Emily Zielinski-Gutierrez of the U.S. Centers for Disease Control and Prevention says residents should still take precautions to avoid being bitten by mosquitoes.